This invention relates to a centrifugal clutch which can transmit rotation of a primary shaft on the input side to a secondary shaft on the output side by utilizing a centrifugal force which results from the rotation of the primary shaft.
So far a centrifugal clutch has also been employed to transmit rotation from a shaft to another. However, in the conventional, common centrifugal clutch, a plurality of arms are swingably fixed to a primary shaft with pins, shoes are rotatably attached to each end of the arms, and a ring of the shoes is enclosed by a cylinder in such a way that the arms can stand upright so as to press the shoes against the inside of the cylinder to transmit rotation of the primary shaft to the secondary shaft by a centrifugal force resulting from the rotation of the primary shaft.
Accordingly, such a centrifugal clutch needs lubricating from time to time to ensure it a good operating condition because most of the joints in the machine are made of metal and connected with pins. This structure has also obliged a user to waste a lot of time in maintenance. Besides, if a user neglects to accurately align both axes of the primary and the secondary shafts on a line, the shoes cannot be brought into even contact with the inside of the cylinder.
Under these circumstances, a first object of this invention is to provide a centrifugal clutch which can be put into operation far more easily than a conventional one in which pins and arms are employed.
A second object of this invention is to provide a centrifugal clutch which needs no lubrication and operates silently. A third object of this invention is to provide a centrifugal clutch which is able to absorb a torsional vibration that follows the transmission of a driving force.
A fourth object of this invention is to provide a centrifugal clutch which permits a driving force to be transmitted effectively even if there is a little offset between the respective axes of the primary and the secondary shafts.
A fifth object of this invention is to provide a centrifugal clutch having a strong coupling force which can well withstand transmitting a large torque.